Evaluating Resources for Global Cluster
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Overview
This topic provides recommended practices and resource evaluation guidelines for Multi-Cluster in .
Proper node sizing ensures the global cluster can efficiently manage all registered clusters, handle synchronization traffic, and process user API and Web Console requests without performance degradation.
Node Sizing
The Global cluster is responsible for:
- Maintaining cluster registration and metadata.
- Handling inbound API requests from the Web Console and CLI.
- Coordinating synchronization and heartbeat messages with managed clusters.
- Managing internal controllers and resource reconciliation loops.
Because the Global Cluster must handle both management operations and data aggregation from all connected clusters, resource allocation should be planned according to the expected scale and workload intensity.
Baseline Production Sizing
The production-scale sizing depends primarily on:
- Number of managed clusters
- Frequency of synchronization cycles
- Concurrent API request rate (from users or automation)
- Volume of streaming requests
- Number of plugins installed
The following table provides reference configurations validated through internal performance testing.
| Scale Tier | Managed Clusters | Number of Nodes | CPU per Node | Memory per Node | Notes |
|---|---|---|---|---|---|
| Small | ≤ 10 | 3 | 8 cores | 16 GB | Suitable for small-scale environments |
| Medium | ≤ 50 | 3 | 16 cores | 32 GB | Default production setup |
| Large | ≤ 100 | 3 | 24 cores | 48 GB | Supports heavy Web Console usage and frequent sync cycles |
| Extra Large | ≤ 500 | 6 | 32 cores | 64 GB | Requires horizontal scaling and dedicated infra nodes |
These recommendations are general guidelines. Actual requirements depend on your cluster topology, user concurrency, and plugins installed.
Vertical Scaling Guidelines
When increasing load per node (for example, 2× more clusters or higher user concurrency), follow these adjustments:
| Parameter | Scaling Recommendation |
|---|---|
| CPU | +50% for every 50 additional managed clusters |
| Memory | +50% for every 50 additional managed clusters |
Horizontal Scaling Guidelines
When exceeding 100 managed clusters or encountering persistent API latency above 500 ms:
Add nodes to distribute request handling and controller workloads.
Resource Validation and Monitoring
After deployment, continuously monitor the following metrics to validate node sizing:
| Metric | Recommended Range |
|---|---|
| Node CPU utilization | 60–75% under peak load |
| Node Memory utilization | ≤80% sustained |
| API request latency | P90 < 500ms |
| etcd commit latency | P99 < 50ms |
If sustained resource usage consistently exceeds recommended thresholds, scale vertically (add CPU/memory) or horizontally (add nodes) before user-facing performance degradation occurs.
Summary
When sizing the Global Cluster:
- Begin with 3 nodes × 16 cores × 32 GB for moderate-scale deployments (≤50 clusters).
- Scale vertically for higher request concurrency or heavy Web Console usage.
- Scale horizontally beyond 100 clusters to maintain API responsiveness.
- Re-evaluate sizing after every significant increase in managed cluster count or sync frequency.
Following these guidelines ensures predictable performance and operational stability as your Multi-Cluster environment grows.